Numerical Analysis of Blockage and Optimization of Heat Transfer Performance of Fractal-like Microchannel Nets

2005 ◽  
Vol 128 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Xiang-Qi Wang ◽  
Arun S. Mujumdar ◽  
Christopher Yap
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Flow Resistance ◽  
Heat Transfer Performance ◽  
Three Dimensional ◽  
Constant Heat Flux ◽  
Low Flow ◽  
Flow And Heat Transfer ◽  
Computational Fluid Dynamics Cfd ◽  
Number Of Branches

The conjugate fluid flow and heat transfer characteristics of fractal-like microchannel nets embedded in a disk-shape heat sink are investigated using a three-dimensional computational fluid dynamics (CFD) approach. A constant heat flux is applied to the top wall of the heat sink. The intrinsic advantages of fractal-like microchannel nets such as low flow resistance, temperature uniformity, and reduced danger of blockage compared with the traditional parallel channel nets are demonstrated. In addition, various optimized designs with parameters such as the number of branches, number of branching levels, and number of channels that reach the center of the disk are addressed in this context.

Effect of Inter-Connector on Thermo-Hydraulic Characteristics of Parallel and Counter Flow Mini-Channel Heat Sink

2018 ◽  
Author(s):  
Amitav Tikadar ◽  
Saad K. Oudah ◽  
Azzam S. Salman ◽  
A. K. M. M. Morshed ◽  
Titan C. Paul ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Conjugate Heat Transfer ◽  
Single Phase ◽  
Three Dimensional ◽  
Cross Flow ◽  
Constant Heat Flux ◽  
Hydraulic Characteristics ◽  
Counter Flow ◽  
Flow And Heat Transfer

A numerical investigation of three-dimensional conjugate heat transfer was performed to quantify the thermal and hydraulic performance of an inter-connected parallel and counter flow mini-channel heat sink under laminar flow condition and within the single-phase regime. The aspect ratio (height/width) and the hydraulic diameter of the mini-channel were 0.33 and 750μm respectively. Three different widths of the inter-connector were selected to analyze the effect of cross flow for Reynolds number ranging from 150 to 1044, at a constant heat flux (20 W/cm2). To understand the fluid flow and heat transfer mechanism inside the inter-connector and their effects on overall thermal performance of the heat sink, Nusselt number (Nu), friction factor, pumping power, and overall thermal resistance were analyzed. Results show that the inter-connector has significantly higher effect on counter flow mini-channel heat sink than parallel flow mini-channel heat sink.

Numerical Analysis of Impinging Air Flow and Heat Transfer in Plate-Fin Type Heat Sinks

1999 ◽  
Vol 123 (3) ◽  
pp. 315-318 ◽  
Author(s):  
Keiji Sasao ◽  
Mitsuru Honma ◽  
Atsuo Nishihara ◽  
Takayuki Atarashi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Numerical Analysis ◽  
Numerical Method ◽  
Heat Sink ◽  
Flow Resistance ◽  
Air Flow ◽  
Heat Sinks ◽  
Flow And Heat Transfer ◽  
Conventional Methods

A numerical method for simulating impinging air flow and heat transfer in plate-fin type heat sinks has been developed. In this method, all the fins of an individual heat sink and the air between them are replaced with a single, uniform element having an appropriate flow resistance and thermal conductivity. With this element, fine calculation meshes adapted to the shape of the actual heat sink are not needed, so the size of the calculation mesh is much smaller than that of conventional methods.

Optimization of Flow and Heat Transfer for a New Double-Layered Microchannel Heat Sink

2019 ◽  
Author(s):  
Huanling Liu ◽  
Bin Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Microchannel Heat Sink ◽  
Transfer Performance ◽  
Temperature Uniformity ◽  
Flow And Heat Transfer ◽  
Fluent Simulation ◽  
New Type ◽  
Improved Design

Abstract In this paper, we propose a new type of DL-MCHS to improve the substrate temperature uniformity of the microchannel heat sink, and conduct the optimization of the New DL-MCHS. The heat transfer and friction characteristics of the novel DL-MCHS are studied by numerical simulation. We compare the heat transfer performance the new DL-MCHS with the traditional TDL-MCHS (the DL-MCHS with truncated top channels λ = 0.38). The results prove the effectiveness of the improved design by FLUENT simulation. When the inlet velocity is kept constant and coolant is water, the heat transfer performance of the New DL-MCHS is higher than that of TDL-MCHS leading to an increase of the temperature uniformity. In order to achieving the best overall heat transfer performance, an optimization of New DL-MCHS is performed by GA (genetic algorithm).

The Effects of Arrangement of Longitudinal Vortex Generators on the Flow and Heat Transfer in the Rectangular Channel

2014 ◽  
Vol 694 ◽  
pp. 205-210
Author(s):  
Nan Cai ◽  
Li Ting Tian ◽  
Chun Hua Min ◽  
Cheng Yin Qi
Keyword(s):  
Heat Transfer ◽  
Flow Resistance ◽  
Heat Transfer Performance ◽  
Rectangular Channel ◽  
Vortex Generator ◽  
Vortex Generators ◽  
Longitudinal Vortex ◽  
Flow And Heat Transfer ◽  
Rectangular Channels ◽  
Flow Drag

In this paper, the heat transfer performance and flow resistance characteristics of the asymmetric arrangement of the rectangular winglet longitudinal vortex generators in the rectangular channels are numerically studied. Results show that at Re=500~2000, comparing with the symmetric arrangement of the longitudinal vortex generator, the Nusselt number of the asymmetric arrangement of the longitudinal vortex generator only decreased by 4% ~ 6%,while,the friction factor f decreases by 11% ~ 22%,the effect of flow drag reduction is very obvious. The asymmetric arrangements of the longitudinal vortex generators show the better overall thermal performance with the increase of j/f by 5% ~ 20%.

Three-Dimensional Analysis of Fluid Flow and Heat Transfer in the Microchannel Heat Sink Using Additive-Correction Multigrid Technique

2008 ◽  
Author(s):  
Omid Asgari ◽  
Mohammad Hassan Saidi
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Large Scale ◽  
Three Dimensional ◽  
Equation System ◽  
Microchannel Heat Sink ◽  
Poisson Equations ◽  
Acceleration Technique ◽  
Flow And Heat Transfer ◽  
Additive Correction

Heat generation from very large-scale integrated (VLSI) circuits increases with the advent of high-density integrated circuit technology. One of the promising techniques is liquid cooling by using microchannel heat sink. Numerical works on the microchannel heat sink in the literature are mostly two dimensional. The purpose of the present study is to develop a three-dimensional analysis procedure to investigate flow and conjugate heat transfer in the microchannel-based heat sink for electronic packaging applications. The micro-heat sink model consists of a 10 mm long silicon substrate, with rectangular microchannels, 57 μm wide and 180 μm deep, fabricated along the entire length. A finite volume numerical code with a multigrid technique, based on additive correction multigrid (AC-MG) scheme, that is a high-performance solver, was developed to solve the steady incompressible laminar Navier–Stokes (N–S) equations, over a colocated Cartesian grid arrangement. The results indicate that thermophysical properties of the liquid can significantly influence both the flow and heat transfer in the microchannel heat sink. Comparison of the numerical results with other published numerical results and experimental data available in the literature for Reynolds numbers less than 200 based on a hydraulic diameter of Dh = 86 μm and Dh/Lx<0.01, indicates that the assumption of hydrodynanmic, fully developed laminar flow is valid. The current research indicates that the AC-MG acceleration technique is highly efficient, reliable and robust, which makes it feasible for CPU-intensive computations, such as pressure Poisson equations. When compared to the discretized momentum equations, the pressure Poisson equations tend to be very stiff and ill-conditioned, i.e ap ≡ Σnb anb Because of these reasons, solving the pressure Poisson equation is usually the CPU bottle-neck for the incompressible N–S equation system and AC-MG technique is required. With this acceleration technique the residuals of the large-scale algebraic equation system are guaranteed to be continuously driven down to the level of the computer machine round-off error and warrants strong conservations of mass and momentum satisfied over all the control volumes. In this cell centered multigrid algorithm both restriction and prolongation operators are based on piecewise constant interpolation. The accuracy of the prediction has been verified by comparing the results obtained with the numerical and analytical results from the open literature.

Numerical Study of Laminar Flow and Heat Transfer Characteristic in Wave Tubes Based on Sine Curve

2011 ◽  
Vol 322 ◽  
pp. 349-352
Author(s):  
Zheng Ming Tong ◽  
Kai Zhu ◽  
Jia Lei Lu ◽  
Gen Li
Keyword(s):  
Heat Transfer ◽  
Flow Resistance ◽  
Numerical Study ◽  
Transfer Characteristic ◽  
Flow State ◽  
Field Synergy Principle ◽  
Corrugated Tube ◽  
Flow And Heat Transfer ◽  
New Type ◽  
Computational Fluid Dynamics Cfd

A new type of corrugated tube based on sine function is proposed by introducing a parameter of sine camber in this paper. Computational Fluid Dynamics (CFD) was used to analysis flow state and sine camber of tube influence on the heat transfer and flow. The heat transfer and flow around sinusoidal corrugated tubes with different sine camber e are investigated. According to the numerical calculus result, correlation equations of Nu (Nusselt) =f(Re) is given. At last, the theoretical comparative analysis with field synergy principle is carried out for the heat transfer and flow resistance in smooth tube and sinusoidal corrugated tube.

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